var openMonth = '';

function toggleMonth(id) {
    if(document.getElementById(id).style.display == 'none') {
        document.getElementById(id).style.display = 'block';
        if(openMonth != '' && openMonth != id) {
            document.getElementById(openMonth).style.display = 'none';
        }
        openMonth = id;
    }
    else {
        document.getElementById(id).style.display = 'none';
        openMonth = '';
    }
}

function hideMonths() {
    for(var i=0; i < document.getElementsByTagName('table').length; i++) {
        if(document.getElementsByTagName('table')[i].className ==
           'calendarMonth') {
            document.getElementsByTagName('table')[i].style.display = 'none';
        }
    }
}

var now = new Date();
var monthNr = new Array('01', '02', '03', '04', '05', '06', '07', '08', '09',
                        '10', '11', '12');
hideMonths();
toggleMonth('anchor_' + now.getFullYear() + '-' + monthNr[now.getMonth()]);